Indications and Limitations of Standalone Percutaneous Vertebroplasty for Reverse Chance Fractures Associated With Ankylosing Spinal Disorders

BACKGROUND: Reverse Chance fractures (RCFs) of the ankylosed thoracolumbar spine present significant therapeutic challenges. The preexisting frailty of these patients, who are typically older individuals with medical morbidities, often outweighs the biomechanical benefit of surgical fixation using spinal instrumentation. We propose that such injuries without displacement or fractures of the posterior elements are reasonable candidates for standalone percutaneous vertebroplasty (PVP) as we have described in our earlier report of 3 cases. To further determine the indications and limitations of standalone PVP for RCFs of the ankylosed spine, we added 5 more cases and investigated the clinicoradiographic outcomes. METHODS: We analyzed the cases of 8 patients with an RCF of their ankylosed thoracolumbar spine. Seven patients had a 2-column fracture, and the other patient had a 3-column fracture. Two of the 7 patients with 2-column fractures had an incomplete fracture at the adjacent vertebra. The patient with the 3-column fracture underwent a standalone PVP under local anesthesia owing to severe heart disease. RESULTS: Of the 7 patients with 2-column fractures, 5 reported immediate pain relief after the PVP. Of these 5 patients, fracture healing was confirmed by computed tomography in all but 1 patient. In the remaining 2 patients with 2-column fractures, an adjacent incomplete fracture collapsed after a PVP was performed, resulting in further enlargement of the open-mouth-type vertebral cleft of the post-PVP vertebra. These patients underwent surgical fixation using instrumentation. The patient with a 3-column fracture obtained pain relief with the PVP, but fracture healing was not achieved until 14 months after PVP. CONCLUSIONS: Standalone PVP plays a role in the treatment of RCFs associated with ankylosing spinal disorders as an alternative to surgical fixation using instrumentation or conservative measures. The presence of the posterior hinges with unfractured facet joints and the lack of an adjacent vertebral fracture are critical indications for a standalone PVP. CLINICAL RELEVANCE: This study presents a treatment option for RCFs associated with ankylosing spinal disorders.